The primary mission of the Norris Cotton Cancer Center (NCCC) Irradiation Shared Resource (ISR) is to provide ionizing radiation services in support of basic and translational cell and animal experiments for the NCCC research community. The availability of a variety of radiation sources continues to allow the ISR to offer a broad and versatile irradiation capability with a wide range of energies and dose rates. The ISR operates multiple experimental and clinical irradiators, including a Cs-gamma source (12,000 Curie, Cs-137), an orthovoltage x-ray source (Pantak multiple energy, 300 KV x-irradiator), four linear accelerators from 6-20 MeV photons and 5-18 MeV electrons and an lr-192 high dose rate after-loader. Linear accelerator capabilities include Cone Beam CT, stereotactic radiosurgery and cardiac/respiration gated therapy. The ISR previously developed a number of advanced imaging instruments and services that now have been split off to constitute a developmental core in advanced animal imaging. The ISR currently provides 25 NCCC Pis and their laboratories with irradiation services. NCCC users represented 81% of the total laboratories using this facility at Dartmouth (25/31 labs total) for FY 2007, and their usage constituted 95% of the total based on units of use. Although the ISR provides critical support for certain NCCC projects and is cost-effective compared with the cost to individual labs to maintain and operate such irradiation sources independently, the overall user base is relatively small and specialized. Thus, the ISR requires a disproportionate level of support from the CCSG and other sources relative to its chargeback revenues. Fees are kept as low as practical, based on user feedback as to what researchers are able and willing to pay on a fee-for-service basis for these irradiations (e.g., fees would have to raise five-fold in order to recover total costs) and also based on comparisons with other institutions. Total chargebacks for this core were $15,466 for FY 2007, representing 17% of the total revenues, and the total operating budget was $91,869, requiring -$76,403 in subvention, derived from the NCCC Core Grant ($64,356, 70%) and other institutional resources ($12,047, 13%). The ISR is requesting a budget of $70,600 from the NCCC Core Grant for the first year of this renewala level comparable to the current year's supportfor its total estimated operating budget for FY 2009 of approximately $89,523. The ISR continues to provide a variety of irradiation services for cell culture and experimental animal experiments to meet the needs of NCCC investigators, who are its principal users. The cesium irradiator continues to be the most heavily used irradiation service of the ISR. Although less heavily used, the clinical radiation sources have proved invaluable for specific projects, the overall goal of the ISR is to continue to support NCCC cancer researchers with these services at as low a rate as possible so that they can continue to successfully meet their research objectives individually and collectively.